Recording and reproducing mechanism for phonographs



W. H. GILMAN.

RECORDING AND REPRODUCING MECHANISM FOR PHONOGRAPHS.

APFLICATSON FILED ocr. 13. 1919. RENEWED JULY 19, 1921.

1,889,430. Patented Aug. 30,1921.

2 SHETSSHEET 1.

W. H. GILMAN. mzconnma AND REPRODUCING M cHAN|sM FOR PHONOGRAPHS.

APPLICATION FILED OCT. 13. I919- RENEWED JULY I9, I92!- Patented Aug. 30, 1921.

2 SHEETSSHEET 2.

1 1 fix UNITED STATES PATENT OFFICE.

WILLARD H: GILMAN, OF NEW YORK, N. Y., ASSIGNOR, BY MESNE ASSIGNMENTS,

TO JOHN A, MCVIGKAR, OF

NEW YORK, N. Y.

RECORDING AND REPRODUCING MECHANISM FOR PHONOGRAPHS.

Specification of Letters Patent. Patented Aug. 30, 1921.

Application filed October 13, 1919, Serial No. 330,464. Renewed July 19, 1921. Serial No. 485,847. I

To all whom it may concern:

Be it known that I, WILLARD H. GILMAN, a citizen of the United States, and resident of New York, in the county of New York and State of New York, have invented certain new and useful Improvements in Recording and Reproducing Mechanisms for Phonographs, of which the following is a specification.

This invention relates to phonographs,

and more particularly to a mechanism which may be used as an attachment to phonographs of standard make, or incorporated in the mechanism of the phonograph itself, for making and reproducing records of the disk type. Among other things its objects are to provide a mechanism which will accurately drive the stylus or operating jewel connected with the diaphragm across the face of the record so as to follow a closely formed spiral on the face of the record; a means whereby the stylus may be accurately positioned anywhere on said spiral; a convenient means whereby the stylus may be elevated from the record; a means whereby the elevation of the stylus suspends its driving operation; a means whereby the stylus is automatically elevated and its driving operation suspended when it reaches a predetermined point on the face of the record; a means whereby the stylus receives its driving motion from the turntable of the phonograph; a means for compensating for eccentricity and irregularities of this drive, a means for adjusting the mechanism for various sizesof turntable and height of rec- 0rd; a means for rapidly removing the mechanism from and replacing it on the turntable of the phonograph and a means for produ cing' a continuous voice passage from a fixed speaking tube to the moving diaphragm."

Other objects will appear from the following specification and drawings in which, Figure 1 is a side elevation of the mechanism partly in section applied. to a phonograph, Fig. 2 is a plan view correspond ing to Fig. 1 withlpart of the cover seca side elevation of the releasing mechanism.

This mechanism includes a friction clutch with a universal joint attached to the center stem of the turntable and by means of a worm gear and horizontal shaft, the rotation of the turntable is transmitted by a reduction gear to a vertical shaft near the edge of the record. This shaft carries the tone arm and as it rotates it moves the tone arm from the edge toward the center of the record causing the stylus to make a close spiral on the surface of the record as it rotates. By a cam action this vertical Shaft may be elevated and through a friction clutch released from the driving mechanism. This movement also raises the tone arm from the record. The mechanism turns on a pivot and may be turned over the body to clear the turntable for replacing records.

In the drawings 11 indicates thetop of a disk type phonograph, 12 is the turntable, 13 is the stem driven by the mechanism of the phonograph (not shown) which rotates the turntable and 14 is a wax record rotating with the turntable.

The mechanism 21 has a base plate 22 and a cover casting 23 which house and protect certain moving parts of the mechanism. A hollow shoe 24 engages the record and rotates therewith by means more .fully described hereafter. The stem of this shoe is pivoted vertically between the base plate 22., and the cover 23 and carries the worm 25 engaging the worm wheel 26 mounted on horizontal shaft 27. This shaft is pivoted in the cover'2 which engages Worm.wheel 29. This construction provides for the rotation of wheel 29 from the rotation of the turntable at a greatly reduced speed.

The worm wheel 29 is loosely mounted on yerticalshaft 30; to this shaft the clutch pin 32. This memher engages a concave and carries the worm 28 forming a friction clutch. A coil spring 33 holds the clutch in engagement and it is declutched by the movement of the slide 37 which is provided with the incline 38; a movement to the right by pressure on lug 36 moves the incline under the loose collar 40 forcing it upward to engage the screw 39 thereby elevating the shaft 30 and releasing the clutch member 31 from the wheel 29, the latter being prevented from rising by the rim 34 cast integral with the cover 23. When this slide is moved back by pressure on lug 35 the incline is removed from under the collar 40 and spring 33 restores the friction clutch in be observed that when the friction clutch is released shaft 30 shaft 30 and is subject to the is not driven by the stem of they turntable.

Fig. 3 shows a plan view of the releasing slide. This is guided to slide in a horizontal plane by a groove in the boss of the casting 23, the top of the slide 37 being flush with the projecting sides of the boss. A slotted opening for shaft 30 permits the sliding motion and limits its extent.

The vibrations of the record are transmitted by a device known as a tone arm 44 supporting the diaphragm casing 46. This tone arm is attached by aball joint to the voice tube 43 and secured by the pivot screws 45 so as to have a free vertical motion. This voice tube is carried by the foot 42 of the movements of this shaft; that is to say the motion of the stem of the turntable can be used to move the diaphragm and the stylus '47 slowly across the face of the record about the center 30 describing the are indicated by the dotted line a. The simultaneous rotation of the turntable and the rotation of shaft 30 causes stylus 47 to inscribe a finely divided spiral groove on the face of the record. The elevation of shaft 30 artially raises the stylus from the record. his effect, however, is increased by the lever effect secured by the bent piece 48 fixed to the tone arm 44. When the foot 42 is raised this piece engages the base plate 22 thus turning the tone arm on pivots 45 and raising stylus 47 from the record with a comparatively large clearance.

It has been stated that raising the shaft 30 releases the friction clutch and thus leaves the tone arm entirely free to be moved toany position on the record. This is an important feature of my invention as it enables the stylus to be accurately positioned in any groove of the record without back-lash or lost motion.

An index 82 is provided on the base plate 22 over which the pointer 81 carried by the tone arm moves to indicate the position of the latter on the record.

When the tone arm moves toward the center of the record it is'essential that its motion be stopped before engaging the center stem of the turntable. This is provided for by the releasing pin 83 in the foot 42 of shaft engaging the incline 84 of the casting 51, Fig. 5, also shown projected in detail A.

As this pin rides up the incline the friction clutch is released by raising the foot 42, this action also raises the tone arm from the record as above described.

The casting 51 is screwed to the base plate 22 at 53 and is therefore a fixed part of the instrument, the speaking tube is connected to the stem 52 of this casting through which the opening 64 is provided connecting with the circular chamber indicated by the broken line 91, Fig. 5. Intersecting one side of this chamber is the foot 42 moving on and with the shaft 30. This foot is a cylindrical hollow member through which the voice tube 43 passes and the end opening indicated at 92 of this tube connects with the circular opening 91. It will thus be observed that while foot 42 may move through a considerable angle a clear and unobstructed passage is provided for the sound which, however, is

confined within the voice duct as defined by the circular opening 91. It is thus possible to attach the speaking tube to a fixture of the mechanism while the tone arm is free to move.

It has been stated that the mechanism is driven from the stem of the turntable by means of afriction clutch. This is illustrated in Figs. 1' and 4. It is found in practice that the stem of these machines seldom runs true, usually there is a certain degree of eccentricity which, if not provided for, would cause the mechanism to oscillate and produce a corresponding motion in the stylus of the tone arms. I provide for this by a special form of universal joint having a friction sleeve 71 with saw cuts 72 which grips the stem 13 by a spring action. A pin 73 passes through the head of this stem' and through the slots 77 in the shoe 24, rounded fillers 74 are placed on the ends of pin 73 and take up the space 78 between the sleeve 71 and the shoe 24. Pin 73 transmits the rotation of sleeve 71 to shoe 24 while the space 78 permits a certain amount of eccentricity of sleeve 71 that is not imparted to shoe 24. This shoe, therefore, rotates in a vertical and rigid position as maintained by the screw 59. The stem 13 is usually of a definite length but the height of the record 14 may vary, a centering washer 79 is provided in the record of a universal thickness, the friction sleeve 71 is forced over the stem 13 by means of pin 73 until it engages this washer thus providing. a substantial friction surface for driving the mechanism; the slot 77 however, permits the elevation. of shoe 24 toaccommodate the various thickness of record. This arrangement also establishes a constant height from the surface of the record to the base of the instrument and thus automatically maintains thestylus of the tone arm in fixed relation to the surface of the record as it may be worn down. a

The mechanism is secured to the top of the phonograph by the flange 63, the end of screw 59 fits .a jawed opening in flange 63 and is secured in position by knurled nut 62. Arm 58 is threaded on screw 59 and can, therefore, be elevated or lowered .by turning knurled nut 60 and releasing nut 62 to permit screw 59 to rotate. A lock nut 61 secures this arm in position and prevents any tendency of the arm to rotate on screw 59. The casting 51 has a flat extension 54 to which the hinge piece 55 is secured byscrews sin f horizontal adjustment in the hinge piece 55 friction sleeve 71 performing both of these functions. present invention shows a .tone arm in out- 2. In a mechanism of the 56 in slotted openings as shown,.this hinge piece pivots to thearm 58 at 57; the arm 58 thus supports one f-end of the mechanism and its height may be adjusted so as to maintain the base of the mechanism horizontal for records of any thickness and thus maintain the proper angle on the stylus of the tone arm. This mechanism may be applied to phonographs having turntables varying rom seven to twelve inches in diameter, the

is provided to enable flange 63 to be moved out from the center to clear the longer turntables. When this attachment is applied to a phonograph it is a convenience to be able to fix the sleeve 71 in the center of shoe '(5 so that the position of flange 63 may thereby be more accurately located, this is secured by moving the sleeve upward within the shoe so that the head engages the opening 7 6 and is thereby .alined In this position it can be applied to a turntable before the record'is used, to position the flange-63.

The whole mechanism, it will be noted turns on the pivot 57, it-oan therefore be easily pulled away from the stem 13 and turned over so as to clear the turntable for renewing records. It is replaced by simply bringing it back into position and forcing onto stem 13. The tone arm may be used for recording or reproducing, or acombination tone arm may be nls fid e line only it being understood that various types of tone arm maybe used with this mechanism, the tone arm itself not being a part of the present invention.

By the use of this invention it is possible to enhance the value of present disk type phonographs byan attachment that converts them into a recording as well as reproducthat is simple to use, easy to ing machines, apply and may be quickly and entirely removed from the phonograph. Having thus described my invention I claim 1. In a mechanism of the class described, the combination with a phonograph having a turntable with a stem, of a device detachably secured to the top of said phonograph and including a friction clutch, a tone arm pivoted vertically in said device and arranged to move in an arcacross the face of said turntable, a driving mechanism forsaid tone 'arm 'operatin g through sa1d friction clutch, 1 said driving mechanism connected with the end of said stem.

class described, tlie combination with a phonograph turntable of a vertical shaftand a friction clutch, said shaft driven from "the stem of said turntable through said friction clutch, "a tone arm. 0' ried by said vei'tical shaft across the fae said turntable-andmeans for rewith the stem of the shoe.

.said friction clutch whereby said stylus may leasing said friction clutch by the move ment of said tone arm.

3. Ina mechanism of the class described, the combination with a phonograph having a turntable with a stem, of' a device detachahly secured to the top of said phonograph and including a friction clutch, a tone arm pivoted vertically in said device and arranged to move in an arc across the face of said turntable, a driving mechanism for said tone arm connected with the end of said stem and operating through said friction clutch and means for releasing said friction clutch and raising said tone arm from the record.

4. In a mechanism of the class described, the combination with a phonograph having a turntable with a stem, of a device detachably secured to the top of said phonograph and including a friction clutch, a tone arm pivoted vertically in said device and arranged to move in an arc across the face of said turntable, a stylus carried by said tone arm and following a finely divided spiral on the face of said record and means including be positioned in any groove of said spiral. 5. In a mechanism of the class described, the combination with a phonograph turntable supporting a record, of a vertical shaft and a friction clutch, said shaft driven from the stem of said turntable, a tone arm carried by said vertical shaft across the face'of said record, and means for automatically releasing s id friction clutch when said tone arm has loved to a predetermined position on said record. (p

6. Ina mechanism of the class described, the combination with a phonograph turntable supporting a record, of a spring clutch engaging the stem, of said turntable, a shaft and a friction clutch, said shaft driven by reductiongearing from said spring, clutch through said friction clutch, a tone arm carried by said shaft across the face of said rec- 0rd, means for applying said spring clutch and means for releasing said friction clutch.

7. In a mechanism of the class described, the combination with a phonograph turntable supporting a record, of a spring clutch engaging the stem of said turntable, a ver tical shaft located near theedge of said turntable, a friction clutch, said shaft driven from said spring clutch through said friction clutch, and a tone arm caried by said shaft across the face of said record to follow turntable, having a stem, a

\back on said support turntable and arranged to move said tone arm in the arc of a circle, means positioning said tone arm at a uniform height from the surface of said record and means for engaging said spring clutch uniformly with records of different thickness.

9. In a mechanism of the class described, the combination with a phonograph, of a turntable, an attachment including a mechanism supported at one end from the center of said turntable and at the other end from a support secured to said phonograph, a pivot connection between said mechanism and said last mentioned support, said mechanism having a vertical shaft and carrying a tone arm to move across said turntable in the arc of a circle, said mechanism belng turnable on sa d pivot to clear said turntable.

10. In a mechanism of the class described,

the combination'with a phonograph, of turntables of various diameters, a mechanism having a vertical shaft carrying a tone arm' pivoted to move across said turntable in the arc of a circle and supportedat one end from the center of said turntable and at the other end from a support secured to said phonograph, means for changing the posi: tion of said last mentioned support with relation to the center support whereby said mechanism may be adapted to the diameter of said turntable. I

11. In a mechanism of the class described, the combination with a phonograph turntable, of a device engaging turntable, a mechanism detachably secured to the top of said phonograph having a vertical member carrying a tone arm across said turntable in the arc of a circle, a universal joint connecting'said device with said mechanism whereby a steady motion is imparted to said tone'arm.

12. In a mechanism of the class described, the combination with a phonograph, of a device detachably secured to a support on the top of said phonograph close to and extending above said turntable, a horizontal arm pivoted vertically to said device and arranged to move across the of a circle, means for moving said tone arm, a voice duct; to said tone arm fixed to said device and means for maintaining said voice duct to said movable tone arm.

13. In a mechanism of the class described, the combination with a phonograph, of a turntable, having a stem, a device detachably secured to a support on the top of said phonograph, said device pivoted to turn to clear said turntable, a tone arm rotatably supported by said device, and driven from said stem, a horizonthe stem of said face of said turntable in the arc,

tal voice duct to said tone arm fixed to said device, an expanded chamber in said horizontal voice duct and the end of said tone arm moving within said chamber.

14. In a mechanism of the class described, the combination with a phonograph, of a turntable supporting a record, a mechanism supported at one end from the center of said record and at the other end from a support secured to said phonograph, said record having a centering washer on its lower surface to fit the stem of said turntable, a spring clutch engaging the stem of said turntable and operating said mechanism and a space in said record above saidwasher to permit said spring clutch to engage said stem.

15. In a mechanism of the class described, the combination with a phonograph, of a turntable supporting ajrecord, a mechanism supported from the center of said record by a shoe, said .hollow shoe having parallel slots, a spring clutch within said hollow shoe engaging the stem of said turntable and a pin connecting said spring clutch with said par-' allel slots.

16. In a mechanism of the class described, the combination with a phonograph turn- .table, a mechanism supported by a hollow shoe from the center of said turntable a spring clutch within said hollow shoe engaging the stem of said turntable, a universal jointconnection between'said shoe and said spring clutch and means whereby said spring cllutch may be rigidly locked in said hollow s oe.

17. In a mechanism of the class described, the combination with a phonograph turntable of a mechanism including a vertical shaft and a friction clutch, said shaft driven through said clutch from the stem of said turntable, a tone arm carried by said vertical shaft, a sliding member having an inclined plane incorporated in said mechanism and meansincluding said sliding member for releasing said friction clutch. v

18. In a mechanism of the class described,

the combination with a phonograph turntable of an attachment including, a mechanism with a spring clutch engaging the stem of said turntable, a universal joint, a worm gear, a horizontal shaft, a second worm gear,

a friction clutch a vertical shaft, said vertical shaft driven from'the stem of said turntable through said universal joint, worm j nd frlction clutch,

Yorkzand State of New Yorkthis'g'Yth day of October A. v 

